Open a climbing gym in Asia.
I wouldn't use OSB for a commercial application. Actually, I would use a dedicated wall builder. see below.
Can you describe your market a little more? Is it a city? A suburban area outside a city? The middle of nowehre? Rich area? Poor area? Competing gyms? This will help guide the decisions you need to make regarding how big your space needs to be, how much wall you need to build, and other things like staffing, hours, rates, etc.
I would use Walltopia, Eldorado, or Rockwerx to build your climbing walls. They prefabricate their walls and ship them to you in sections, and their crew will show up and assemble the wall in your space. They will also help guide you through the process of opening a gym. I don't know what the climbing wall builder market is like in Asia, but it would probably be prohibitively costly in money and time to design, engineer, and build a (quality) climbing wall yourself or with a regular general contractor who has never done anything like it before. Not to mention all the other little things about running a gym that an established industry player could help you with. Out of the three mentioned above Walltopia is probably the best bet as they regularly build climbing walls for gyms all over the world. They are absolutely dominant in your native Europe, so I'm sure you have climbed on their walls before.
The climbing gym scene in South Korea is exploding, and I bet there are some Chinese companies too, if you wanted to check those places out for wall builders. Im sure there are some, I just don't know of them.